Footwear construction

ABSTRACT

A footwear construction including a midsole frame having a forefoot base, a heel base and an intermediate frame section that connects the forefoot base and the heel base. The forefoot base and heel base can be separated from one another by a frame void. The forefoot base can include at least one forefoot base void extending across the width, of the footwear to improve flexibility of the footwear. The construction also can include a midsole including a lower surface housed at least partially within and/or joined with the midsole frame, with the midsole frame forefoot base and a heel base separated from one another below the midsole lower surface by the frame void, and connected above the lower surface by the intermediate frame section. Where the construction includes an outsole, that outsole can define an outsole forefoot void, which can be aligned with the forefoot base void.

BACKGROUND OF THE INVENTION

The present invention relates to footwear and, more particularly, to a footwear construction and a method for making the same.

In the footwear industry, there is an ongoing effort to produce footwear that provides a high level of stability and support, while maintaining exceptional comfort. This effort is heightened in the design of high performance footwear, such as watersport, hiking, mountaineering, multisport and rugged outdoor walking footwear. To minimize the effects of travel over jagged, rugged or uneven surfaces high performance footwear is frequently provided with components that provide torsional stability (e.g. resistance to twisting forces) and longitudinal stability (e.g. resistance to linear forces).

Conventionally, stability and comfort have been competing characteristics. Efforts to improve stability and support typically result in a reduction in flexibility in the shoe, and subsequently comfort. A common technique for improving stability in watersport footwear, such as high performance sandals, is to provide a sole assembly including a single continuous midsole, which extends from toe to heel of the footwear and a single, continuous, high-grip outsole, which likewise extends from toe to heel of the footwear. The midsole is rigid enough to provide the above mentioned torsional and longitudinal stability. To the midsole, a leather or synthetic, upper is joined by stitching. The upper extends upward from the midsole and over the top of the wearer's forefoot. There, the opposing sides of the upper are joined with a lace system which secures the footwear to the wearer's foot.

While this construction—particularly its sole assembly—increases stability, it commonly reduces the comfort and wearability of the footwear. For example, the rigid midsole typically provides very limited cushioning and therefore results in reduced comfort. Further, the rigid midsole generally Is unable to flex along the longitudinal axis of the footwear which extends from toe to heel generally along the center of the footwear. Accordingly, with each step, the wearer must exert sufficient force to bend the midsole. This can increase fatigue in the wearer's foot muscles. As a result, there remains a long felt and unmet need for a footwear construction that provides the desired level of stability and support, as well as comfort and flexibility.

SUMMARY OF THE INVENTION

The aforementioned problems are overcome by a footwear construction including a midsole frame having a forefoot base, a heel base and an intermediate frame section that connects the forefoot base and the heel base. In one embodiment, the forefoot base and heel base also are separated from one another by a frame void.

In another embodiment, the forefoot base can include at least one forefoot base void extending across the width of the footwear to improve flexibility of the footwear.

In a farther embodiment, the construction can include a midsole including an upper surface and a lower surface. The midsole is housed at least partially within and/or joined with the midsole frame, with the midsole frame forefoot base and a heel base separated from one another below the midsole lower surface by the frame void, and connected to one another above the lower surface by the: intermediate frame section.

In yet another embodiment, the construction can include an outsole secured to the midsole frame. The forefoot portion of the outsole can define at least one outsole forefoot void, which can be aligned with the forefoot base void. Optionally, the outsole can be separated into an outsole forefoot portion and an outsole heel portion separated from one another by an outsole void.

In yet a further embodiment, the footwear construction can include an upper and a closure, with me closure secured to a portion of the midsole frame, optionally to the intermediate frame section* to further secure the footwear to a wearer's foot.

The construction described herein provides a novel footwear having a high degree of support, as well as improved flexibility and comfort. The midsole frame and its components add structured stability and firmness to the footwear. These characteristics are particularly advantageous in high performance and other footwear. With the one or more voids included in the midsole frame and/or the outsole, an added level of flexibility can be provided without compromising the structural stability of the footwear.

These and other objects, advantages and features of the invention will be more readily understood and appreciated by reference to the detailed description of the preferred embodiments and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of footwear of a first embodiment;

FIG. 2 is a bottom exploded perspective view of the footwear;

FIG. 3 is a bottom perspective view of the footwear;

FIG. 4 is a side view of the footwear;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4; and

FIG. 6 is a sectional view taken along line 6-6 of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION I. Overview

Footwear constructed in accordance with a preferred embodiment is shown in FIGS. 1-6 and generally designated 10. The footwear 10 includes an upper 20 joined with a midsole 30, which is further joined with a midsole frame 50, which is joined with an outsole 90. A closure 40 can be joined with the midsole frame 50 and/or upper 20 to further secure the footwear on the foot of a wearer. The midsole frame 50 can include a forefoot frame base 52 and a heel frame base 54, which are joined by an intermediate frame section 60. Optionally, a plate 70 can be included in the footwear between the midsole 30 and the midsole frame 50. The midsole frame 50 and outsole 90 can each include voids SO, 82, 84 and 91, 92, 94, which are generally aligned with one another, respectively. When included, these voids can provide improved flexion of the footwear along the longitudinal axis A of the footwear to reduce fatigue on the wearer's foot.

For purposes of disclosure, the present invention will be described in connection with a watersport sandal. As will be appreciated, the present invention is well suited for use with any other type of soled footwear, including other multi-sport footwear, outdoor footwear, walking footwear, athletic footwear and work footwear.

II. Structure

The components of the sandal 10 will now be described in more detail. The upper 20 is generally conventional and includes quarters 22 and a vamp 24, which can be separate or integral components. As shown in FIG. 1, the upper can be constructed to wrap from one side of the wearer's foot, over the top of the forefoot, and back down the other side of the foot. The peripheral edge portions 26 can be secured to the upright flanges 34 and 36 extending from the midsole 30 by any conventional means, such as adhesives, stitching, staples, fusion and the like. Optionally, the upper can also include a heel portion 28 that extends from the quarters 22, wrapping around the rear of the wearer's heel or Achilles tendon to provide additional securement of the footwear to a wearer's foot. Further optionally, the upper can extend over an cover the wearer's toes to provide a closed toe footwear (not shown). Finally, the upper 20 can be absent from the footwear altogether as desired. The upper can be constructed from any suitable material such as neoprene, EVA, plastic, mesh fabric, canvas, leather or any other suitable material.

The midsole 30 to which the upper 20 is secured is generally formed in the shape of a wearer's foot. The midsole can include forward and rearward upstanding flanges 34 and 36, respectively, which serve to provide a point of attachment of the upper to the midsole. These flanges can be absent from the construction as desired, with the upper secured directly to the base portion 38 of the midsole by any conventional fastening construction. Opposite the upper surface 35 of the midsole is a lower surface 37, which extends from one side of the footwear corresponding to the outside of a wearer's foot, to another side of the footwear, corresponding to the inside of a wearer's foot, across a width of the bottom, of the midsole. The midsole also can extend from the forward most portion of the footwear to the rearward most portion of the footwear.

The midsole 30 and other components of the footwear 10 can he constructed from a resilient and semi-rigid synthetic material, for example, polyurethane. Polyurethane is generally well known in footwear industry; therefore, it will not be described in detail here. The rigidity and flexibility of polyurethane can be varied from application to application as desired using a variety of well-known techniques, such as by adjusting the type, proportion and amount of the reactant to make-up the material. In addition, the rigidity and flexibility of the polyurethane can be varied by adjusting the volume of polyurethane used. Although polyurethane is a preferred midsole material, the density and precise chemical make-up of the midsole material will vary depending on a variety of factors, including the size of the midsole and the desired cushioning and flexibility characteristics of the footwear.

As shown hi FIG. 2, the lower surface 37 of the midsole optionally can include a recess 38. This recess can be configured to accept a plate 70. The recess can be configured to be of a depth sufficient to position the plate 70 in a desired location, or as deep as the plate itself.

The optional plate 70 can be constructed to extend from, the forefoot 100 of the footwear to the arch portion 110, and to the heel portion 120 if desired. As shown, however, the plate extends from the forefoot portion toward the heel portion, but terminates within the heel portion. Thus, as shown, the plate extends only part of the distance from the toe to heel of the footwear. In addition, the plate can include one or more projecting regions 72 that project from the generally planar structure of the plate 70. These projecting regions can be configured to register with the voids defined by the midsole frame, and/or outsole as described below. The plate can be constructed from any semi-rigid and/or rigid but flexible material. Optionally, such material can be plastic, high density EVA, polyurethane, hard rubber and the like.

The optional plate can also be configured to form around an optional heel button recess 39 also defined in the midsole 30 on its lower surface 37. Within the heel button recess, a heel button 76 can be located. This heel button can be of any size, or shape, for example, circular, square, elliptical, triangular, etc. and constructed from any suitable, heel cushioning material, for example low density EVA.

The midsole frame 50 can include a forefoot frame base 52 and a heel frame base 54, which are joined by an intermediate frame section 60. The forefoot frame base 52 and heel frame base 54 are optionally joined substantially only by the intermediate frame section 60. Indeed, the forefoot base 52 and heel base 54 can be separated by a frame void 80 when the bases are in a common plane or in different planes. The forefoot frame base 52 includes a forefoot wall 53, which extends upward from the upper surface 57. The forefoot frame base 52 can also define frame voids. These forefoot frame voids 82 and 84 can be defined by the bottom 51 of the forefoot base 54, as well as: the forefoot wall 53. In the forefoot wall 53, the voids 82 and 84 can widen as desired.

The heel frame base 54, shown in FIGS. 2 and 3 can include a heel wall 55 that extends upward from the upper surface 59 of the heel frame base 54. As shown, this heel wall 55 can extend upward from the base 54 in select regions. Accordingly, portions of the side wall 33 of the midsole 30 remain exposed to viewers of the footwear between the base and the intermediate frame section 60. If desired, the heel wall 55 can extend upward from the heel base 54 around the entire periphery of the base, and optionally can conceal the midsole side wall 33.

With reference to FIGS. 1 and 2, the intermediate frame section 60 connects the forefoot frame base 52 and the heel frame base 54. The section 60 can be joined with any portion of these bases as desired, for example, the forefoot wall 53 and the heel wall 55. FIG. 2 shows that the section 60 is connected to a rearward portion of the heel wall 55 and a rearward portion of the forefoot wail 53. Further, it is illustrated that the heel base to the forefoot base can be connected by substantially only the section 60 (on both sides of the footwear), and that all of these components can be formed from one, integral piece as desired.

The intermediate frame section 60 is shown as an arch-shaped component; however, it can be of any other geometric configuration as desired, for example, a portion of a quadrilateral or a triangle. As shown, a portion of the intermediate frame section 60 extends a distance above both the fore foot frame base 52 and the heel frame base 54, this section 60 can also extend above the plate 70 and upper surface 35 of the midsole 30 a selected distance. In one embodiment, the section 60 is adjacent the quarters 22 of the upper 20.

The intermediate frame section 60 illustrated in FIGS. 1, 4, and 5 can further include apertures 67 that receive the portions of the closure 40, which as shown, are straps that are part of a lacing system. The apertures 67 can vary in size and shape from that shown depending on the desired attributes of the closure 40. In addition, the intermediate frame section 60 can define one or more heel strap apertures 69 through which a heel strap 75 can be positioned to further secure the footwear to the wearer's heel.

Optionally, the lower surfaces of the forefoot frame base 52 and the heel frame base 54 can include alignment ridges 59. As shown in FIGS. 2 and 3, these alignment ridges are immediately adjacent the voids 82 and 84. The ridges 59 can be used to align the outsole with the midsole frame, and in particular, to align the outsole voids 92 and 94 with the midsole frame voids 82 and 84.

The intermediate frame section 60 can he constructed from polyurethane, EVA, plastic, synthetic materials, rubber, combinations of the foregoing, or any other material as desired. In addition, the frame can be constructed using injection molding techniques, or any other technique as desired.

With reference to FIGS. 2 and 3, the outsole 90 is constructed from a relatively hard, but gripping rubber or other sufficiently durable and wear-resistant material. The outsole 90 includes bottom 99 which forms a wearing surface of the outsole 90 and may be contoured to define a desired tread pattern. Moreover, the bottom may be textured to improve the traction and aesthetic appeal of the shoe. The outsole 90 is substantially flat, however, it may also include one or more peripheral walls 93, 95 extending upwardly along the medial and/or lateral sides and/or in the heel or forefoot of the shoe. As shown, these outsole walls extend upwardly along the side walls of the midsole frame in the forefoot and heel regions of the footwear. Specifically, the outsole wall 93 extends upward along the forefoot wall 53 in the forefoot frame base 52, and the outsole wall 95 extends upward along the heel wall 55 in the heel frame base 54.

As illustrated in FIG. 3, the outsole 90 optionally can be divided into two separate portions; a heel portion 96 and a forefoot portion 97. These portions can be separated by an outsole void 91. The forefoot and heel portions can include additional voids. For example, as shown, forefoot portion 97 defines forefoot voids 92 and 94. These voids are defined by the bottom 99 of the forefoot portion 97, as well as the outsole wall 93. In the outsole wall 93, the voids 92 and 94 can widen as desired.

With reference to FIGS. 2, 3 and 6, the forefoot voids 92 and 94 of the outsole are aligned with the forefoot frame voids 82 and 84 of the midsole frame 50. In addition, where included, the projecting region 72 can project slightly into at least one of the voids defined by the midsole frame and the outsole. Optionally, the outsole 90 can be an integral component of the midsole frame 50, in which case, the voids extend through the midsole frame to the lowermost portion of the frame, which also forms the ground contacting surface of the footwear 10.

Referring to FIGS. 1 and 4, the footwear 10 can optionally include a closure 40. As shown, the closure is a lacing system, including a lace 42 and lace straps 44, which are secured to the intermediate frame section 60 through the apertures 67. The closure 40 optionally can include a pressure pad 49 to distribute the pressure on the wearer's forefoot when the closure is tightened. In addition, a lace lock 46 can be included in the system as desired to ensure that the system remains tightened. Although the closure 40 is shown as a lacing system, it can be substituted entirely or in part by hook and loop closure systems, ratcheting closure systems, straps, strapping systems and snap closure systems.

III. Manufacture

Manufacture of the footwear 10 will now be described with reference to FIGS. 1-3. In general, each of the components, that is, the midsole 30, the midsole frame 50, the plate 70, and outsole 90 can be formed using conventional techniques such as injection molding. The components are allowed to cure, and then trimmed and cleaned with a well known cleaning agent. In addition, the upper 20 is formed using conventional cutting and stitching techniques. With the components thus made, they are assembled.

Specifically, the upper 20 is secured to the rearward upstanding flanges 34 and 36 of the midsole 30 using any conventional fastening apparatus, such as cement, adhesive, and/or stitching. The flex plate 70 and heel button 76 can be further secured to the midsole 30 with cement or other adhesives as desired.

In addition, the outsole parts, that is, the heel portion 96 and a forefoot portion 97, can be secured to the respective heel frame base 54 and forefoot frame base 52 with cement and/or adhesives or other molding techniques. The midsole 30 with the assembled upper 20 can be secured to me midsole frame 50 with the attached outsole. In one embodiment, the midsole 30 is secured so that the intermediate frame section 60 projects upward and is adjacent the upper 20. Excess cement and/or adhesives used to join the components can be cleaned and removed from the footwear 10.

With the components assembled, the closure 40 and heel strap 75 can be secured to the midsole frame 50 to complete the footwear. Thereafter, the article of footwear is readied for subsequent processing, packaging and shipping.

The above descriptions are those of the preferred embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any references to claim elements in the singular, for example, using the articles “a,” “an,” “the,” or “said,” is not to be construed as limiting the element to the singular. 

1. A footwear construction comprising: an upper; a midsole joined with the upper; a midsole frame joined with the midsole, the midsole frame including a forefoot frame base, a heel frame base and an intermediate frame section integral with and., connecting the forefoot frame base and the heel, frame base, the forefoot frame base defining at least one forefoot frame base void, the forefoot frame base and the heel frame base separated from one another by a frame void, the intermediate frame section extending upward from the heel frame base and the forefoot frame base and located at least partially above the midsole; a closure secured to the midsole frame, the closure disposed over a portion of the upper and adapted, to secure the footwear to a wearer's foot; and an outsole secured to the midsole frame, the outsole including an outsole forefoot portion and ah outsole heel portion, which are separate elements that are separated from one another by an outsole void, the outsole void aligned with the frame void, the outsole forefoot, portion secured the forefoot frame base, the outsole heel portion, secured to the heel frame base, the outsole forefoot portion defining an outsole forefoot void which is aligned with the forefoot frame base void.
 2. The footwear construction of claim 1 wherein the midsole includes an upper surface and a lower surface and wherein the intermediate frame section extends at least partially above the lower surface.
 3. The footwear construction of claim 1 wherein the midsole includes an upper surface and a lower surface and wherein the lower surface defines a least one of a plate recess and a heel button recess.
 4. The footwear construction of claim 3 comprising at least one of a plate positioned in the plate recess and a heel button positioned in the heel button recess.
 5. The footwear construction of claim 1 wherein the midsole frame defines at least one lace aperture and wherein the closure includes a lace secured at least partially to the at least one lacing aperture.
 6. The footwear construction of claim 1 wherein the midsole forefoot frame base defines a second forefoot frame base void, and the outsole forefoot portion defines a second outsole forefoot void, which is aligned with the second forefoot frame base void.
 7. A footwear construction comprising: a midsole including an upper surface and a lower surface; a midsole frame including a forefoot base and a heel base separated from one another below the lower surface by a frame void, and connected to one another above the lower surface by an intermediate frame section; a closure secured to the midsole frame and adapted to further secure the footwear to a wearer's foot; and an outsole joined, with at least one of the midsole frame and the midsole.
 8. The footwear construction of claim 7 wherein the outsole is at least one of integral with the midsole frame and non-integral with the midsole frame.
 9. The footwear construction of claim 7 wherein the outsole includes an outsole forefoot portion and a separate outsole heel portion, the outsole heel portion secured to the heel base and the outsole forefoot portion secured to the forefoot base, the outsole forefoot portion separated from the outsole heel portion by an outsole void.
 10. The footwear construction of claim 9 wherein the outsole forefoot portion defines a first outsole forefoot void and the forefoot base defines a first forefoot base void, the first outsole forefoot void and the first forefoot base void aligned with one another.
 11. The footwear construction of claim 7 comprising a plate joined with the midsole lower surface.
 12. The footwear construction of claim 11 wherein the outsole defines a first outsole forefoot void and the forefoot base defines a first forefoot base void, the first outsole forefoot void and the first forefoot base void aligned with one another, wherein at least a portion of the plate is exposed through the aligned first outsole forefoot void and the first forefoot base void.
 13. The footwear construction of claim 7 comprising an upper secured to the midsole, the intermediate frame section projecting upward and adjacent at least a portion of the upper.
 14. A footwear construction comprising: an upper; a midsole frame Including a forefoot base and a heel base separated from one another below the upper by a frame void, the forefoot base and heel base connected to one another by an intermediate frame section, the intermediate frame section extending upward above the forefoot base and heel base, adjacent at least a portion of the upper, the forefoot base defining a forefoot base void; and an outsole joined with the midsole frame, the outsole defining an outsole forefoot void which is aligned with the forefoot base void.
 15. The footwear construction of claim 14 wherein the outsole is at least one of integral and non-integral with the midsole frame.
 16. The footwear construction of claim 14 wherein the outsole includes an outsole forefoot portion and an outsole heel portion.
 17. The footwear construction of claim 14 comprising a flex plate positioned adjacent the midsole.
 18. The footwear construction of claim 17 wherein the flex plat is positioned between the midsole frame and the outsole.
 19. The footwear construction of claim 14 comprising a midsole secured to the upper.
 20. The footwear construction of claim 14 comprising a closure secured to the midsole frame above the closure being above at least a portion of the upper. 